1. Technical Field
The present invention relates to a liquid crystal display and an electronic apparatus.
2. Related Art
As a light modulation device of various electro-optical devices, a liquid crystal display is used, and in recent years, it is widely used for various purposes. Such a liquid crystal display includes a transflective liquid crystal display which includes a reflective display mode using external light and a transmissive display mode using an internal light source, such as a backlight, as a display mode. The transflective liquid crystal display selectively uses one display mode of a reflective mode and a transmissive mode in accordance with ambient brightness. In this case, power consumption can be reduced, and clear display can be performed even in the dark.
In the transflective liquid crystal display, a phase difference is likely to be produced between a region for reflective display (reflective display region) and a region for transmissive display (transmissive display region) due to different display methods. For this reason, in general, a phase layer for phase adjustment is provided, and optical compensation is performed.
However, the phase difference of the phase layer depends on a viewing angle. For this reason, even if the phase difference is optimized in a direction normal to the phase layer, an optimum compensation condition is not attained as increasing distance from the direction normal to the phase layer. As a result, the viewing angle becomes narrow.
Accordingly, with respect to such a transflective liquid crystal display, it has been studied that a transverse electric field driving liquid crystal display having a wide viewing angle is applied in order to increase the viewing angle (for example, JP-A-2005-338256 and JP-A-2007-212498). In the transverse electric field mode, an in-plane (transverse) electric field is generated with respect to a substrate, and liquid crystal molecules are rotated by the transverse electric field within a plane parallel to the substrate, thereby controlling light to be transmitted. The transverse electric field mode includes an IPS (In-Plane Switching) mode and an FFS (Fringe-Field Switching) mode, which is an improvement of the IPS mode.
According to the method described in JP-A-2005-338256, a phase layer is formed so as to be patterned only in the reflective display region, thereby providing an internal phase layer. Thus, the transmissive display region has a wide viewing angle. According to the method described in JP-A-2007-212498, optical compensation is performed by a phase layer with the direction of a slow axis thereof controlled, and a liquid crystal layer thickness adjusting layer is provided in order to make the thickness of the liquid crystal layer in the reflective display region smaller than the thickness of the liquid crystal layer in the transmissive display region. Both display regions are different in the thickness of the liquid crystal layer. In this way, light to be transmitted is arranged to have an equal optical path length, and the phase difference is eliminated. As a result, high-quality image display is realized.
The phase layer or the liquid crystal layer thickness adjusting layer described in the above-described documents is formed by patterning an ultraviolet curable material. When the phase layer or the liquid crystal layer thickness adjusting layer is patterned, the end portion of the phase layer or the liquid crystal layer thickness adjusting layer slopes. The above-described documents illustrate a liquid crystal display in which the end portion of the phase layer or the liquid crystal layer thickness adjusting layer slopes.
If a region where such a slope portion is formed is present in the reflective display region, an optical characteristic of the corresponding region is different from that of a region, which is formed flat as designed, and accordingly an optical condition for dark display is not attained. When this happens, light leakage occurs from the region where the slope portion is formed. Light leakage causes an unclear image with contrast deteriorated. Meanwhile, a light-shielding black matrix may be provided so as to overlap the slope portion. In this case, however, the pixel aperture ratio decreases so much. In the case of a high-definition pixel, luminance is deteriorated, and a satisfactory display characteristic is not attained.